Prediction of Failure Path Current for Synchronous Reluctance and Interior Permanent Magnet Synchronous Machines Accounting for Saturation

This paper proposes a model for obtaining the failure path current and torque waveforms in synchronous reluctance and interior permanent magnet synchronous machines under inter-turn short circuits (ISC). The variations of the magneto motive force (MMF) due to an ISC can lead to considerable changes in the inductances, which could lead to errors when modeling motors with ISC. A dynamic model is introduced, which uses rotor reference frame variables and parameters as inputs. Saturation is included by incorporating a look-up table, thus accounting for the MMF variations due to an ISC. Finally, the proposed model is compared with finite element analysis showing good agreement.